package gui;


/**
THIS PROGRAM IS PROVIDED "AS IS" WITHOUT ANY WARRANTIES (OR CONDITIONS),
EXPRESS OR IMPLIED WITH RESPECT TO THE PROGRAM, INCLUDING THE IMPLIED WARRANTIES (OR CONDITIONS)
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK ARISING OUT OF USE OR
PERFORMANCE OF THE PROGRAM AND DOCUMENTATION REMAINS WITH THE USER.
*/
import java.awt.*; import java.util.*;
/**
 *
 * A vertical layout manager similar to java.awt.FlowLayout.
 * Like FlowLayout components do not expand to fill available space except when the horizontal alignment
 * is <code>BOTH</code>
 * in which case components are stretched horizontally. Unlike FlowLayout, components will not wrap to form another
 * column if there isn't enough space vertically. VerticalLayout can optionally anchor components to the top or bottom
 * of the display area or center them between the top and bottom.
 *
 * Revision date 12th July 2001
 *
 * @author Colin Mummery  e-mail: colin_mummery@yahoo.com Homepage:www.kagi.com/equitysoft -
 * Based on 'FlexLayout' in Java class libraries Vol 2 Chan/Lee Addison-Wesley 1998
 */

public class VerticalLayout implements LayoutManager{

/**
* The horizontal alignment constant that designates centering. Also used to designate center anchoring.
*/
	public final static int CENTER=0;
/**
* The horizontal alignment constant that designates right justification.
*/
	public final static int RIGHT=1;
/**
* The horizontal alignment constant that designates left justification.
*/
	public final static int LEFT=2;
/**
* The horizontal alignment constant that designates stretching the component horizontally.
*/
	public final static int BOTH=3;

/**
* The anchoring constant that designates anchoring to the top of the display area
*/
	public final static int TOP=1;
/**
* The anchoring constant that designates anchoring to the bottom of the display area
*/
	public final static int BOTTOM=2;
	private int vgap; //the vertical vgap between components...defaults to 5
	private int alignment; //LEFT, RIGHT, CENTER or BOTH...how the components are justified
	private int anchor; //TOP, BOTTOM or CENTER ...where are the components positioned in an overlarge space
	private Hashtable comps;

//Constructors
/**
* Constructs an instance of VerticalLayout with a vertical vgap of 5 pixels, horizontal centering and anchored to
* the top of the display area.
*/
   public VerticalLayout(){
	this(5,CENTER,TOP);
   }
/**
* Constructs a VerticalLayout instance with horizontal centering, anchored to the top with the specified vgap
*
* @param vgap An int value indicating the vertical seperation of the components
*/
   public VerticalLayout(int vgap){
	this(vgap,CENTER,TOP);
   }
/**
* Constructs a VerticalLayout instance anchored to the top with the specified vgap and horizontal alignment
*
* @param vgap An int value indicating the vertical seperation of the components
* @param alignment An int value which is one of <code>RIGHT, LEFT, CENTER, BOTH</code> for the horizontal alignment.
*/
   public VerticalLayout(int vgap,int alignment){
	this(vgap,alignment,TOP);
   }
/**
* Constructs a VerticalLayout instance with the specified vgap, horizontal alignment and anchoring
*
* @param vgap An int value indicating the vertical seperation of the components
* @param alignment An int value which is one of <code>RIGHT, LEFT, CENTER, BOTH</code> for the horizontal alignment.
* @param anchor An int value which is one of <code>TOP, BOTTOM, CENTER</code> indicating where the components are
* to appear if the display area exceeds the minimum necessary.
*/
   public VerticalLayout(int vgap,int alignment,int anchor){
	this.vgap=vgap; this.alignment=alignment; this.anchor=anchor;
   }
//----------------------------------------------------------------------------
   private Dimension layoutSize(Container parent,boolean minimum){
	Dimension dim=new Dimension(0,0);
	Dimension d;
	synchronized(parent.getTreeLock()){
		int n=parent.getComponentCount();
		for(int i=0;i<n;i++){
			Component c=parent.getComponent(i);
			if(c.isVisible()){
				d=minimum ? c.getMinimumSize() : c.getPreferredSize();
				dim.width=Math.max(dim.width,d.width); dim.height+=d.height;
				if(i>0)dim.height+=vgap;
			}
		}
	}
	Insets insets=parent.getInsets();
	dim.width+=insets.left+insets.right;
	dim.height+=insets.top+insets.bottom+vgap+vgap;
	return dim;
   }
//-----------------------------------------------------------------------------
/**
 * Lays out the container.
 */
   public void layoutContainer(Container parent){
	Insets insets=parent.getInsets();
	synchronized(parent.getTreeLock()){
		int n=parent.getComponentCount();
		Dimension pd=parent.getSize(); int y=0;
//work out the total size
		for(int i=0;i<n;i++){
			Component c=parent.getComponent(i);
			Dimension d=c.getPreferredSize();
			y+=d.height+vgap;
		}
		y-=vgap; //otherwise there's a vgap too many
//Work out the anchor paint
		if(anchor==TOP)y=insets.top;
		else if(anchor==CENTER)y=(pd.height-y)/2;
		else y=pd.height-y-insets.bottom;
//do layout
		for(int i=0;i<n;i++){
			Component c=parent.getComponent(i);
			Dimension d=c.getPreferredSize();
			int x=insets.left; int wid=d.width;
			if(alignment==CENTER)x=(pd.width-d.width)/2;
			else if(alignment==RIGHT)x=pd.width-d.width-insets.right;
			else if(alignment==BOTH)wid=pd.width-insets.left-insets.right;
			c.setBounds(x,y,wid,d.height);
			y+=d.height+vgap;
		}
	}
   }
//-----------------------------------------------------------------------------
   public Dimension minimumLayoutSize(Container parent){return layoutSize(parent,false);}
//-----------------------------------------------------------------------------
   public Dimension preferredLayoutSize(Container parent){return layoutSize(parent,false);}
//----------------------------------------------------------------------------
/**
 * Not used by this class
 */
   public void addLayoutComponent(String name,Component comp){}
//-----------------------------------------------------------------------------
/**
 * Not used by this class
 */
   public void removeLayoutComponent(Component comp){}
//-----------------------------------------------------------------------------
   public String toString(){return getClass().getName()+"[vgap="+vgap+" align="+alignment+" anchor="+anchor+"]";}
}

